1. Field of the Invention
The disclosed embodiments of the invention relate generally to a filter to be added to lighting fixtures and around light sources used for illumination purposes, and more particularly, to lighting fixtures and diode light sources used in buildings and transportation vehicles (i.e. automobiles, motorcycles, trains and planes) for the purpose of general illumination and accent illumination.
2. Description of the Related Art
General illumination in buildings and within transportation vehicles is primarily from lighting fixtures. These lighting fixtures use either fluorescent, incandescent or a HID lighting source.
When a lighting source lamp burns-out, it must be replaced. Typically a fluorescent lamp will need to be replaced every 15,000 hours, an incandescent lamp every 2000 hours, and a high intensity discharge (HID) lamp every 20,000 hours. Associated ballast replacement occurs every five years. The cost to conduct such maintenance and replacement can be expensive as well as disruptive to the occupants.
Lighting fixtures also deteriorate over time. Fixtures, and particularly metal fixtures, can be scraped or bent during maintenance or when an object strikes the fixture. This deterioration over time reduces fixture performance and fixture aesthetics.
Lighting fixture physical depth is critical in construction. Fixtures that encroach excessively into the cavity above the ceiling can interfere with construction of electrical and other systems.
In addition to maintenance, the cost of operating a fixture is tied directly to its energy use. Many municipalities also have restrictions on the amount of energy that can be allocated to general and accent illumination by lighting fixtures.
Light sources produce light at a specific range of wavelengths. Light at certain wavelengths is not desirable because it can shift the color of the object being viewed. In buildings true color (as viewed in sunlight) is the standard reference and thus the desirable color. The light produced by light emitting diodes (LED) is within a wide range of wavelengths. In many applications a specific range of light wavelengths is required for optimum performance, and present LED sources are unable to produce light in the specific range.
Another disadvantage of present LED designs is that LEDs are forward facing and the viewer can thus see the individual LED light sources. Typically these light sources appear as dots, which are not visually appealing and tend to not meet the criteria for illumination appearance desired by most users.
Thus it would be a great benefit to have a building lighting fixture that is virtually maintenance free, is resistant to deterioration of performance over its life span, has a shallow depth, has reduced power consumption, has a softer appearance and can adjust light to a specified range of wavelengths.
Replacing existing fixtures with fixtures containing color-corrected lamps can be quite expensive. In new construction providing fixtures containing color-corrected lamps can also be quite expensive. Color corrected lamps are available but the cost can be high for the lamp and in certain cases expensive for the special ballast needed to drive the color corrected lamp.
Thus there is a need for a filter that can either be added to the fixture and/or surround the lamp source to block undesirable wavelengths while allowing desirable wavelengths through.
The illumination source of transportation vehicle headlight fixtures and interior cab light fixtures is primarily by incandescent and HID lamps, and with limited use of fluorescent lighting. Transportation headlight fixtures are subject to deterioration caused by adverse environments such as rain, soot, and vibration. It would be advantageous to have transportation vehicle headlight fixtures and transportation vehicle interior cab light fixtures that are virtually maintenance free, resistant to deterioration of performance over the life span, have a softer appearance, and can adjust light to a specified range of wavelengths.